---
_id: '64798'
abstract:
- lang: eng
  text: "Lead-containing piezoelectric ceramics are still the base for today’s ultrasonic
    transducers used in broad applications. This is partly due to missing powerful
    lead-free piezoelectric ceramic parts in the commercial market. There has been
    much research on lead-free materials but developing them into marketable parts
    seems to be an ongoing process. The actual exemption of ROHS has expired, but
    as the new exemption has already been requested, ceramic suppliers keep on selling
    lead containing products. Nevertheless, these should be replaced by lead-free
    alternatives for environmental and health issues. \r\nThis contribution focuses
    on exploring the technological readiness level of lead-free hard piezoceramics
    for prestressed ultrasonic transducers. A small series of bolted Langevin transducers
    was set up with standard PZT material and three commercial lead-free variants.
    Results of the building process from individual ring ceramic characteristics to
    transducer load tests are presented. The main finding of this study is that the
    lead-free materials technically can compete with the standard PZT for medium-power
    applications. Some adaptations in the ultrasonic system must be done: the geometry
    must be altered to fit resonance frequency, and higher voltages or thinner ceramics
    are needed to achieve the same vibration level at low load. For reaching same
    power, the volume of lead-free ceramics must be 1.5 to 3 times larger. As already
    promoted in literature, mechanical losses at high vibration levels are smaller
    for the lead-free materials. This might help to argument lead-free piezoelectric
    materials in some applications.\r\n\r\nReferences\r\n1.\tDirective 2011/65/EU
    of the European Parliament and of the Council of 8 June 2011 on the Restriction
    of the Use of Certain Hazardous Substances in Electrical and Electronic Equipment.
    EUR-Lex Document 02011L0065-20240801. Available online: http://data.europa.eu/eli/dir/2011/65/2024-08-01
    (accessed on 24 January 2025).\r\n2.\tLangevin, P. (1918) Method and Apparatus
    for Transmitting and Receiving Submarine Elastic Waves Using the Piezoelectric
    Properties of Quartz. French Patent Office; Patent No. FR505703.\r\n3.\tHemsel,
    T.; Twiefel, J. (2023) Piezoelectric Ultrasonic Power Transducers. In Encyclopedia
    of Materials: Electronics; Academic Press: Oxford, UK; pp. 276–285. https://doi.org/10.1016/b978-0-12-819728-8.00047-4.\r\n4.\tATHENA
    Technologie Beratung GmbH (2025) Description of Ultrasound Generator. Available
    online: http://shop.myathena.de/epages/12074748.sf/de_DE/?ObjectPath=/Shops/12074748/Products/AM200
    (accessed on 13 January 2025).\r\n5.\tLittmann, W.; Hemsel, T.; Kauczor, C.; Wallaschek,
    J.; Sinha, W. (2003) Load-adaptive phase-controller for resonant driven piezoelectric
    devices. Proc. World Congr. Ultrason. 2003, 48, 547–550.\r\n6.\tScheidemann, C.,
    Bornmann, P., Littmann, W., & Hemsel, T. (2025). Lead-Free Ceramics in Prestressed
    Ultrasonic Transducers. Actuators, 14(2), 55. https://doi.org/10.3390/act14020055\r\n"
author:
- first_name: Claus
  full_name: Scheidemann, Claus
  id: '38259'
  last_name: Scheidemann
- first_name: Peter
  full_name: Bornmann, Peter
  last_name: Bornmann
- first_name: Walter
  full_name: Littmann, Walter
  last_name: Littmann
- first_name: Tobias
  full_name: Hemsel, Tobias
  id: '210'
  last_name: Hemsel
citation:
  ama: 'Scheidemann C, Bornmann P, Littmann W, Hemsel T. Bolted Langevin transducers
    with leadfree piezoelectric ceramics. In: ; 2025.'
  apa: Scheidemann, C., Bornmann, P., Littmann, W., &#38; Hemsel, T. (2025). <i>Bolted
    Langevin transducers with leadfree piezoelectric ceramics</i>. International Workshop
    on Piezoelectric Materials and Applications in Actuators (IWPMA), Vilnius, Lithuania.
  bibtex: '@inproceedings{Scheidemann_Bornmann_Littmann_Hemsel_2025, title={Bolted
    Langevin transducers with leadfree piezoelectric ceramics}, author={Scheidemann,
    Claus and Bornmann, Peter and Littmann, Walter and Hemsel, Tobias}, year={2025}
    }'
  chicago: Scheidemann, Claus, Peter Bornmann, Walter Littmann, and Tobias Hemsel.
    “Bolted Langevin Transducers with Leadfree Piezoelectric Ceramics,” 2025.
  ieee: C. Scheidemann, P. Bornmann, W. Littmann, and T. Hemsel, “Bolted Langevin
    transducers with leadfree piezoelectric ceramics,” presented at the International
    Workshop on Piezoelectric Materials and Applications in Actuators (IWPMA), Vilnius,
    Lithuania, 2025.
  mla: Scheidemann, Claus, et al. <i>Bolted Langevin Transducers with Leadfree Piezoelectric
    Ceramics</i>. 2025.
  short: 'C. Scheidemann, P. Bornmann, W. Littmann, T. Hemsel, in: 2025.'
conference:
  end_date: 2025-07-03
  location: Vilnius, Lithuania
  name: International Workshop on Piezoelectric Materials and Applications in Actuators
    (IWPMA)
  start_date: 2025-07-01
date_created: 2026-03-02T10:39:40Z
date_updated: 2026-03-02T11:04:56Z
ddc:
- '620'
department:
- _id: '151'
file:
- access_level: open_access
  content_type: application/pdf
  creator: hemsel
  date_created: 2026-03-02T10:37:46Z
  date_updated: 2026-03-02T11:00:37Z
  file_id: '64799'
  file_name: IWPMA_2025_Hemsel.pdf
  file_size: 1812289
  relation: main_file
file_date_updated: 2026-03-02T11:00:37Z
has_accepted_license: '1'
keyword:
- lead free piezoelectric ceramics
- bolted Langevin transducer
- medium power ultrasound.
language:
- iso: eng
oa: '1'
status: public
title: Bolted Langevin transducers with leadfree piezoelectric ceramics
type: conference
user_id: '210'
year: '2025'
...
---
_id: '33500'
abstract:
- lang: eng
  text: 'This article is dedicated to piezoelectric ultrasonic power transducers that
    differ to well known medical ultrasonic diagnostic apparatus or non destructive
    testing devices by the level of power in use; typically several tens of up to
    more than thousand watts are used in a multitude of different applications. After
    a short introduction including historical development, the first focus is on theoretical
    background of the operating principle, design and mechanical modeling. As piezoelectric
    elements transform electrical to mechanical energy and vice versa, equivalent
    circuit modeling is also described. After that, sample applications are delineated
    by the matter wherein ultrasound generates unique effects: incredible high pressure
    level as well in air as in water, micro-bubbles generating temperature peaks for
    very short time instances in fluids, acoustoplastic effect, enhancement of diffusion
    and recrystallization in solids, friction manipulation, incremental deformation
    and micro-cracking of surfaces, or even generation of macroscopic movements in
    motors. At the end, some future directions ranging from novel modeling approaches
    to advanced control and new materials are addressed.'
author:
- first_name: Tobias
  full_name: Hemsel, Tobias
  id: '210'
  last_name: Hemsel
- first_name: Jens
  full_name: Twiefel, Jens
  last_name: Twiefel
citation:
  ama: 'Hemsel T, Twiefel J. Piezoelectric Ultrasonic Power Transducers. In: <i>Reference
    Module in Materials Science and Materials Engineering</i>. Elsevier; 2022. doi:<a
    href="https://doi.org/10.1016/b978-0-12-819728-8.00047-4">10.1016/b978-0-12-819728-8.00047-4</a>'
  apa: Hemsel, T., &#38; Twiefel, J. (2022). Piezoelectric Ultrasonic Power Transducers.
    In <i>Reference Module in Materials Science and Materials Engineering</i>. Elsevier.
    <a href="https://doi.org/10.1016/b978-0-12-819728-8.00047-4">https://doi.org/10.1016/b978-0-12-819728-8.00047-4</a>
  bibtex: '@inbook{Hemsel_Twiefel_2022, title={Piezoelectric Ultrasonic Power Transducers},
    DOI={<a href="https://doi.org/10.1016/b978-0-12-819728-8.00047-4">10.1016/b978-0-12-819728-8.00047-4</a>},
    booktitle={Reference Module in Materials Science and Materials Engineering}, publisher={Elsevier},
    author={Hemsel, Tobias and Twiefel, Jens}, year={2022} }'
  chicago: Hemsel, Tobias, and Jens Twiefel. “Piezoelectric Ultrasonic Power Transducers.”
    In <i>Reference Module in Materials Science and Materials Engineering</i>. Elsevier,
    2022. <a href="https://doi.org/10.1016/b978-0-12-819728-8.00047-4">https://doi.org/10.1016/b978-0-12-819728-8.00047-4</a>.
  ieee: T. Hemsel and J. Twiefel, “Piezoelectric Ultrasonic Power Transducers,” in
    <i>Reference Module in Materials Science and Materials Engineering</i>, Elsevier,
    2022.
  mla: Hemsel, Tobias, and Jens Twiefel. “Piezoelectric Ultrasonic Power Transducers.”
    <i>Reference Module in Materials Science and Materials Engineering</i>, Elsevier,
    2022, doi:<a href="https://doi.org/10.1016/b978-0-12-819728-8.00047-4">10.1016/b978-0-12-819728-8.00047-4</a>.
  short: 'T. Hemsel, J. Twiefel, in: Reference Module in Materials Science and Materials
    Engineering, Elsevier, 2022.'
date_created: 2022-09-30T09:35:16Z
date_updated: 2022-09-30T09:41:47Z
department:
- _id: '151'
doi: 10.1016/b978-0-12-819728-8.00047-4
keyword:
- Equivalent circuit model
- Langevin transducer
- Lumped parameter model
- Piezoelectric transducer
- Ultrasonic processes
- Ultrasound
language:
- iso: eng
main_file_link:
- url: https://www.sciencedirect.com/science/article/pii/B9780128197288000474
publication: Reference Module in Materials Science and Materials Engineering
publication_identifier:
  isbn:
  - 978-0-12-803581-8
publication_status: published
publisher: Elsevier
quality_controlled: '1'
status: public
title: Piezoelectric Ultrasonic Power Transducers
type: book_chapter
user_id: '210'
year: '2022'
...
---
_id: '9745'
abstract:
- lang: eng
  text: In the modeling of piezoelectric Langevin transducers using usual transfer
    matrix methods, some simplifications have been adopted. This leads to reduction
    of the model quality. A mixed transfer matrix method is employed in the modeling
    of Langevin transducers, where the pre-stressed bolt is modeled as a separate
    four-pole element, which is connected to other elements in parallel. Based on
    the mixed transfer matrix method, the four (six)-pole element description of the
    piezoelectric Langevin transducer is built up and the total transfer matrix relation
    is derived. The resonance frequencies of the transducer are calculated and then
    measured using the impedance analyzer (HP4192). Experimental result shows that
    the mixed transfer matrix method has better modeling quality than the usual transfer
    matrix method for the vibration analysis of piezoelectric Langevin transducers.
author:
- first_name: Bo
  full_name: Fu, Bo
  last_name: Fu
- first_name: Chao
  full_name: Li, Chao
  last_name: Li
- first_name: Jianming
  full_name: Zhang, Jianming
  last_name: Zhang
- first_name: Zhenwei
  full_name: Huang, Zhenwei
  last_name: Huang
- first_name: Tobias
  full_name: Hemsel, Tobias
  id: '210'
  last_name: Hemsel
citation:
  ama: Fu B, Li C, Zhang J, Huang Z, Hemsel T. Modeling of Piezoelectric Langevin
    Transducers by Using Mixed Transfer Matrix Methods. <i>Journal of Korean Physical
    Society</i>. 2010;57(4):929. doi:<a href="https://doi.org/10.3938/jkps.57.929">10.3938/jkps.57.929</a>
  apa: Fu, B., Li, C., Zhang, J., Huang, Z., &#38; Hemsel, T. (2010). Modeling of
    Piezoelectric Langevin Transducers by Using Mixed Transfer Matrix Methods. <i>Journal
    of Korean Physical Society</i>, <i>57</i>(4), 929. <a href="https://doi.org/10.3938/jkps.57.929">https://doi.org/10.3938/jkps.57.929</a>
  bibtex: '@article{Fu_Li_Zhang_Huang_Hemsel_2010, title={Modeling of Piezoelectric
    Langevin Transducers by Using Mixed Transfer Matrix Methods}, volume={57}, DOI={<a
    href="https://doi.org/10.3938/jkps.57.929">10.3938/jkps.57.929</a>}, number={4},
    journal={Journal of Korean Physical Society}, author={Fu, Bo and Li, Chao and
    Zhang, Jianming and Huang, Zhenwei and Hemsel, Tobias}, year={2010}, pages={929}
    }'
  chicago: 'Fu, Bo, Chao Li, Jianming Zhang, Zhenwei Huang, and Tobias Hemsel. “Modeling
    of Piezoelectric Langevin Transducers by Using Mixed Transfer Matrix Methods.”
    <i>Journal of Korean Physical Society</i> 57, no. 4 (2010): 929. <a href="https://doi.org/10.3938/jkps.57.929">https://doi.org/10.3938/jkps.57.929</a>.'
  ieee: B. Fu, C. Li, J. Zhang, Z. Huang, and T. Hemsel, “Modeling of Piezoelectric
    Langevin Transducers by Using Mixed Transfer Matrix Methods,” <i>Journal of Korean
    Physical Society</i>, vol. 57, no. 4, p. 929, 2010.
  mla: Fu, Bo, et al. “Modeling of Piezoelectric Langevin Transducers by Using Mixed
    Transfer Matrix Methods.” <i>Journal of Korean Physical Society</i>, vol. 57,
    no. 4, 2010, p. 929, doi:<a href="https://doi.org/10.3938/jkps.57.929">10.3938/jkps.57.929</a>.
  short: B. Fu, C. Li, J. Zhang, Z. Huang, T. Hemsel, Journal of Korean Physical Society
    57 (2010) 929.
date_created: 2019-05-13T09:40:42Z
date_updated: 2022-01-06T07:04:19Z
department:
- _id: '151'
doi: 10.3938/jkps.57.929
intvolume: '        57'
issue: '4'
keyword:
- Piezoelectric langevin transducer
- Transfer matrix method
- Four (six)-pole element description
- Pre-stressed bolt
language:
- iso: eng
page: '929'
publication: Journal of Korean Physical Society
publication_identifier:
  issn:
  - 1948-5719
quality_controlled: '1'
status: public
title: Modeling of Piezoelectric Langevin Transducers by Using Mixed Transfer Matrix
  Methods
type: journal_article
user_id: '55222'
volume: 57
year: '2010'
...
---
_id: '9749'
abstract:
- lang: eng
  text: Piezoelectric materials find wide application in technical systems. Most often,
    a combination of piezoelectric and other materials is advantageous. The position
    and the amount of the piezoelectric material within the overall system depends
    on various aspects like maximum mechanical output to the load, maximum electromechanical
    efficiency of the system, maximum utilization of the piezoelectric material, minimum
    self-heating of the piezoelectric material, and controllability of the system,
    which might be key aspects for the optimisation of the system design. For a composite
    longitudinal vibrator (bolted Langevin transducer), which is a base for many technical
    applications, this contribution shows in detail, how above mentioned aspects depend
    on the position and volume of the piezoelectric material related to the mode shape.
author:
- first_name: Tobias
  full_name: Hemsel, Tobias
  id: '210'
  last_name: Hemsel
- first_name: Ernst Günther
  full_name: Lierk, Ernst Günther
  last_name: Lierk
- first_name: Walter
  full_name: Littmann, Walter
  last_name: Littmann
- first_name: Takeshi
  full_name: Morita, Takeshi
  last_name: Morita
citation:
  ama: Hemsel T, Lierk EG, Littmann W, Morita T. Various Aspects of the Placement
    of a Piezoelectric Material in Composite Actuators, Motors, and Transducers. <i>Journal
    of Korean Physical Society</i>. 2010;57(4):933-937. doi:<a href="https://doi.org/10.3938/jkps.57.933">10.3938/jkps.57.933</a>
  apa: Hemsel, T., Lierk, E. G., Littmann, W., &#38; Morita, T. (2010). Various Aspects
    of the Placement of a Piezoelectric Material in Composite Actuators, Motors, and
    Transducers. <i>Journal of Korean Physical Society</i>, <i>57</i>(4), 933–937.
    <a href="https://doi.org/10.3938/jkps.57.933">https://doi.org/10.3938/jkps.57.933</a>
  bibtex: '@article{Hemsel_Lierk_Littmann_Morita_2010, title={Various Aspects of the
    Placement of a Piezoelectric Material in Composite Actuators, Motors, and Transducers},
    volume={57}, DOI={<a href="https://doi.org/10.3938/jkps.57.933">10.3938/jkps.57.933</a>},
    number={4}, journal={Journal of Korean Physical Society}, author={Hemsel, Tobias
    and Lierk, Ernst Günther and Littmann, Walter and Morita, Takeshi}, year={2010},
    pages={933–937} }'
  chicago: 'Hemsel, Tobias, Ernst Günther Lierk, Walter Littmann, and Takeshi Morita.
    “Various Aspects of the Placement of a Piezoelectric Material in Composite Actuators,
    Motors, and Transducers.” <i>Journal of Korean Physical Society</i> 57, no. 4
    (2010): 933–37. <a href="https://doi.org/10.3938/jkps.57.933">https://doi.org/10.3938/jkps.57.933</a>.'
  ieee: T. Hemsel, E. G. Lierk, W. Littmann, and T. Morita, “Various Aspects of the
    Placement of a Piezoelectric Material in Composite Actuators, Motors, and Transducers,”
    <i>Journal of Korean Physical Society</i>, vol. 57, no. 4, pp. 933–937, 2010.
  mla: Hemsel, Tobias, et al. “Various Aspects of the Placement of a Piezoelectric
    Material in Composite Actuators, Motors, and Transducers.” <i>Journal of Korean
    Physical Society</i>, vol. 57, no. 4, 2010, pp. 933–37, doi:<a href="https://doi.org/10.3938/jkps.57.933">10.3938/jkps.57.933</a>.
  short: T. Hemsel, E.G. Lierk, W. Littmann, T. Morita, Journal of Korean Physical
    Society 57 (2010) 933–937.
date_created: 2019-05-13T09:56:22Z
date_updated: 2022-01-06T07:04:19Z
department:
- _id: '151'
doi: 10.3938/jkps.57.933
intvolume: '        57'
issue: '4'
keyword:
- Bolted Langevin transducer
- Optimum placement of piezoelectric ceramics
language:
- iso: eng
page: 933-937
publication: Journal of Korean Physical Society
publication_identifier:
  issn:
  - 1948-5719
quality_controlled: '1'
status: public
title: Various Aspects of the Placement of a Piezoelectric Material in Composite Actuators,
  Motors, and Transducers
type: journal_article
user_id: '55222'
volume: 57
year: '2010'
...
---
_id: '9568'
abstract:
- lang: eng
  text: A simple pre-stress estimate method of Langevin transducers is studied. The
    measurement setup consists of a capacitor, an impedance converter and a voltmeter.
    Based on the piezoelectric equation and the basic circuit theory, the mathematical
    expression between the pre-stress and the voltage across the capacitor is derived.
    The pre-stress level can then be calculated out of the measurement of the capacitor
    voltage. In order to evaluate the precision of this method, a force washer is
    used to measure the pre-stress of the Langevin transducer. The result shows the
    pre-stress level obtained from this method is 30-40\% higher than the pre-stress
    level measured by the force washer. This method is simple and can be used to estimate
    the pre-stress of various Langevin transducers. The precision of this method can
    be raised if d33 is identified under different pre-stress levels.
author:
- first_name: Fu
  full_name: Bo, Fu
  last_name: Bo
- first_name: Li
  full_name: Ting, Li
  last_name: Ting
- first_name: Tobias
  full_name: Hemsel, Tobias
  id: '210'
  last_name: Hemsel
citation:
  ama: 'Bo F, Ting L, Hemsel T. A simple pre-stress estimating method of langevin
    transducers. In: <i>Piezoelectricity, Acoustic Waves, and Device Applications,
    2008. SPAWDA 2008. Symposium On</i>. ; 2008:324-327. doi:<a href="https://doi.org/10.1109/SPAWDA.2008.4775801">10.1109/SPAWDA.2008.4775801</a>'
  apa: Bo, F., Ting, L., &#38; Hemsel, T. (2008). A simple pre-stress estimating method
    of langevin transducers. In <i>Piezoelectricity, Acoustic Waves, and Device Applications,
    2008. SPAWDA 2008. Symposium on</i> (pp. 324–327). <a href="https://doi.org/10.1109/SPAWDA.2008.4775801">https://doi.org/10.1109/SPAWDA.2008.4775801</a>
  bibtex: '@inproceedings{Bo_Ting_Hemsel_2008, title={A simple pre-stress estimating
    method of langevin transducers}, DOI={<a href="https://doi.org/10.1109/SPAWDA.2008.4775801">10.1109/SPAWDA.2008.4775801</a>},
    booktitle={Piezoelectricity, Acoustic Waves, and Device Applications, 2008. SPAWDA
    2008. Symposium on}, author={Bo, Fu and Ting, Li and Hemsel, Tobias}, year={2008},
    pages={324–327} }'
  chicago: Bo, Fu, Li Ting, and Tobias Hemsel. “A Simple Pre-Stress Estimating Method
    of Langevin Transducers.” In <i>Piezoelectricity, Acoustic Waves, and Device Applications,
    2008. SPAWDA 2008. Symposium On</i>, 324–27, 2008. <a href="https://doi.org/10.1109/SPAWDA.2008.4775801">https://doi.org/10.1109/SPAWDA.2008.4775801</a>.
  ieee: F. Bo, L. Ting, and T. Hemsel, “A simple pre-stress estimating method of langevin
    transducers,” in <i>Piezoelectricity, Acoustic Waves, and Device Applications,
    2008. SPAWDA 2008. Symposium on</i>, 2008, pp. 324–327.
  mla: Bo, Fu, et al. “A Simple Pre-Stress Estimating Method of Langevin Transducers.”
    <i>Piezoelectricity, Acoustic Waves, and Device Applications, 2008. SPAWDA 2008.
    Symposium On</i>, 2008, pp. 324–27, doi:<a href="https://doi.org/10.1109/SPAWDA.2008.4775801">10.1109/SPAWDA.2008.4775801</a>.
  short: 'F. Bo, L. Ting, T. Hemsel, in: Piezoelectricity, Acoustic Waves, and Device
    Applications, 2008. SPAWDA 2008. Symposium On, 2008, pp. 324–327.'
date_created: 2019-04-29T11:16:13Z
date_updated: 2022-01-06T07:04:16Z
department:
- _id: '151'
doi: 10.1109/SPAWDA.2008.4775801
keyword:
- capacitors
- impedance convertors
- piezoelectric transducers
- stress analysis
- Langevin transducers
- basic circuit theory
- capacitor
- impedance converter
- piezoelectric equation
- pre-stress estimating method
- voltmeter
- Capacitors
- Educational institutions
- Equations
- Force measurement
- Impedance measurement
- Manufacturing
- Mechatronics
- Piezoelectric transducers
- Voltage
- Voltmeters
- Langevin transducer
- capacitor
- piezoelectric element
- pre-stress
language:
- iso: eng
page: 324-327
publication: Piezoelectricity, Acoustic Waves, and Device Applications, 2008. SPAWDA
  2008. Symposium on
status: public
title: A simple pre-stress estimating method of langevin transducers
type: conference
user_id: '55222'
year: '2008'
...